#include <stdio.h>

char ch[]="0101";

int TWO_TEN(char* str);

int main(void)
{
	int Value =0;
	Value =TWO_TEN(ch);
	printf("%d",Value);
	while(1);
	return 0;
}

int TWO_TEN(char* str)
{
	int i =0,dec =0;
	for(i;str[i]!='\0';i++)
		dec =dec*2+(str[i]-'0');
	return dec;
}